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  <div class="section" id="debugging-and-profiling">
<h1>27. Debugging and Profiling<a class="headerlink" href="#debugging-and-profiling" title="Permalink to this headline">¶</a></h1>
<p>These libraries help you with Python development: the debugger enables you to
step through code, analyze stack frames and set breakpoints etc., and the
profilers run code and give you a detailed breakdown of execution times,
allowing you to identify bottlenecks in your programs.</p>
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<ul>
<li class="toctree-l1"><a class="reference internal" href="bdb.html">27.1. <code class="docutils literal"><span class="pre">bdb</span></code> — Debugger framework</a></li>
<li class="toctree-l1"><a class="reference internal" href="faulthandler.html">27.2. <code class="docutils literal"><span class="pre">faulthandler</span></code> — Dump the Python traceback</a><ul>
<li class="toctree-l2"><a class="reference internal" href="faulthandler.html#dumping-the-traceback">27.2.1. Dumping the traceback</a></li>
<li class="toctree-l2"><a class="reference internal" href="faulthandler.html#fault-handler-state">27.2.2. Fault handler state</a></li>
<li class="toctree-l2"><a class="reference internal" href="faulthandler.html#dumping-the-tracebacks-after-a-timeout">27.2.3. Dumping the tracebacks after a timeout</a></li>
<li class="toctree-l2"><a class="reference internal" href="faulthandler.html#dumping-the-traceback-on-a-user-signal">27.2.4. Dumping the traceback on a user signal</a></li>
<li class="toctree-l2"><a class="reference internal" href="faulthandler.html#issue-with-file-descriptors">27.2.5. Issue with file descriptors</a></li>
<li class="toctree-l2"><a class="reference internal" href="faulthandler.html#example">27.2.6. Example</a></li>
</ul>
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<li class="toctree-l1"><a class="reference internal" href="pdb.html">27.3. <code class="docutils literal"><span class="pre">pdb</span></code> — The Python Debugger</a><ul>
<li class="toctree-l2"><a class="reference internal" href="pdb.html#debugger-commands">27.3.1. Debugger Commands</a></li>
</ul>
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<li class="toctree-l1"><a class="reference internal" href="profile.html">27.4. The Python Profilers</a><ul>
<li class="toctree-l2"><a class="reference internal" href="profile.html#introduction-to-the-profilers">27.4.1. Introduction to the profilers</a></li>
<li class="toctree-l2"><a class="reference internal" href="profile.html#instant-user-s-manual">27.4.2. Instant User’s Manual</a></li>
<li class="toctree-l2"><a class="reference internal" href="profile.html#module-cProfile">27.4.3. <code class="docutils literal"><span class="pre">profile</span></code> and <code class="docutils literal"><span class="pre">cProfile</span></code> Module Reference</a></li>
<li class="toctree-l2"><a class="reference internal" href="profile.html#the-stats-class">27.4.4. The <code class="docutils literal"><span class="pre">Stats</span></code> Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="profile.html#what-is-deterministic-profiling">27.4.5. What Is Deterministic Profiling?</a></li>
<li class="toctree-l2"><a class="reference internal" href="profile.html#limitations">27.4.6. Limitations</a></li>
<li class="toctree-l2"><a class="reference internal" href="profile.html#calibration">27.4.7. Calibration</a></li>
<li class="toctree-l2"><a class="reference internal" href="profile.html#using-a-custom-timer">27.4.8. Using a custom timer</a></li>
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<li class="toctree-l1"><a class="reference internal" href="timeit.html">27.5. <code class="docutils literal"><span class="pre">timeit</span></code> — Measure execution time of small code snippets</a><ul>
<li class="toctree-l2"><a class="reference internal" href="timeit.html#basic-examples">27.5.1. Basic Examples</a></li>
<li class="toctree-l2"><a class="reference internal" href="timeit.html#python-interface">27.5.2. Python Interface</a></li>
<li class="toctree-l2"><a class="reference internal" href="timeit.html#command-line-interface">27.5.3. Command-Line Interface</a></li>
<li class="toctree-l2"><a class="reference internal" href="timeit.html#examples">27.5.4. Examples</a></li>
</ul>
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<li class="toctree-l1"><a class="reference internal" href="trace.html">27.6. <code class="docutils literal"><span class="pre">trace</span></code> — Trace or track Python statement execution</a><ul>
<li class="toctree-l2"><a class="reference internal" href="trace.html#command-line-usage">27.6.1. Command-Line Usage</a><ul>
<li class="toctree-l3"><a class="reference internal" href="trace.html#main-options">27.6.1.1. Main options</a></li>
<li class="toctree-l3"><a class="reference internal" href="trace.html#modifiers">27.6.1.2. Modifiers</a></li>
<li class="toctree-l3"><a class="reference internal" href="trace.html#filters">27.6.1.3. Filters</a></li>
</ul>
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<li class="toctree-l2"><a class="reference internal" href="trace.html#programmatic-interface">27.6.2. Programmatic Interface</a></li>
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<li class="toctree-l1"><a class="reference internal" href="tracemalloc.html">27.7. <code class="docutils literal"><span class="pre">tracemalloc</span></code> — Trace memory allocations</a><ul>
<li class="toctree-l2"><a class="reference internal" href="tracemalloc.html#examples">27.7.1. Examples</a><ul>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#display-the-top-10">27.7.1.1. Display the top 10</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#compute-differences">27.7.1.2. Compute differences</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#get-the-traceback-of-a-memory-block">27.7.1.3. Get the traceback of a memory block</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#pretty-top">27.7.1.4. Pretty top</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="tracemalloc.html#api">27.7.2. API</a><ul>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#functions">27.7.2.1. Functions</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#domainfilter">27.7.2.2. DomainFilter</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#filter">27.7.2.3. Filter</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#frame">27.7.2.4. Frame</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#snapshot">27.7.2.5. Snapshot</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#statistic">27.7.2.6. Statistic</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#statisticdiff">27.7.2.7. StatisticDiff</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#trace">27.7.2.8. Trace</a></li>
<li class="toctree-l3"><a class="reference internal" href="tracemalloc.html#traceback">27.7.2.9. Traceback</a></li>
</ul>
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